We replace cracked or loose chimney pots, renew the flaunching they sit in, and fit bird guards, rain caps and cowls. For disused flues we fit a vented cap so rain stays out but the flue can still breathe, which prevents condensation damp; this usually goes with a vent in the room below. For open fires and stoves in use, any cap or cowl must suit the appliance, and we recommend having the flue swept and checked by a qualified chimney sweep.
What do chimney pots, caps and cowls do?
The pot sits on top of the flue to carry smoke and gases clear of the stack and help the flue draw. It is held in place by the flaunching, the sloped mortar around its base. A cap or cowl goes on top of the pot. Different types do different jobs:
- Bird guardsMesh guards that stop jackdaws and other birds nesting in the flue, a common cause of blocked chimneys.
- Rain capsHooded caps that keep rain out of an open flue while letting it vent.
- Vented cappingFor disused flues: a cap that keeps water out but leaves ventilation so the flue can breathe.
- Anti-downdraught cowlsDesigned to reduce wind blowing smoke back down an open fire or stove flue in exposed or awkward positions.
- Replacement potsNew clay pots in a style to suit the house, bedded in fresh flaunching.
Signs your pots or caps need attention
- A pot that is cracked, chipped, leaning or missing its top.
- Broken or crumbling flaunching around the base of the pots.
- Birds going in and out of a pot, twigs falling into the fireplace, or noise in the flue in spring.
- Water, soot stains or debris in an old fireplace or behind a boarded-up opening after rain.
- Damp or brown staining on a chimney breast where the flue is no longer used.
- Smoke blowing back into the room from an open fire on windy days.
Capping a disused flue properly
Many Liverpool homes have chimney breasts with fireplaces that were blocked up years ago. Rain then falls straight down the open flue and soaks the breast, or the flue is sealed solid at the top and at the fireplace so no air can move through it. A sealed flue holds moist air that condenses on the cold masonry, and the result looks just like a roof leak.
The answer is to cap the pot with a vented cap that keeps rain out while letting air pass, and to fit a small vent in the blocked-up fireplace so air can circulate from the room up the flue. If old chimney breasts have absorbed salts from years of coal fires, some damp staining may persist until the plaster is renewed; our chimney problems guide explains how to tell the difference. Where water is clearly getting in elsewhere, our chimney leak repair service traces the source.
Never cap a flue that serves a working fire, stove, boiler or other appliance without confirming it is safe to do so. A flue in use must be able to vent freely. We do not sweep chimneys; for open fires and stoves please use a qualified chimney sweep, who can also advise on suitable cowls for your appliance.
How we replace pots and fit cowls
- Questions first. We ask which flues are in use, what appliances (if any) are connected, and what you have noticed.
- Inspection. We look at the pots, flaunching and stack from the ground, ladder, roof or drone and take photos.
- Recommendation and quote. We explain which pots need replacing, which flues should be capped and with what, and give a written quote.
- Access. A roof ladder, platform or scaffold is used depending on the height and position of the stack.
- Pots and flaunching. Damaged pots are removed and new or reused pots bedded in fresh flaunching that sheds water off the stack.
- Caps and cowls. Guards, caps or cowls are fitted securely to suit each flue.
- Photos. You receive photos of the finished top of the stack.
Pots and cowls on Liverpool chimneys
Terraced streets in Walton, Anfield and Everton often have stacks carrying a row of pots for both houses, many serving fireplaces that have long since been blocked up and left uncapped. Larger villas in Allerton and Aigburth can have tall stacks with several flues where one is still in use for a stove and the others are disused. In exposed coastal spots such as Crosby and Wallasey, wind can cause downdraught problems and loosen pots set in old, cracked flaunching. Birds nesting in pots is a common spring problem across Merseyside.
On a shared stack, the pots belong to different households, so we check which pot serves which flue before capping anything. It is part of the care that goes into our chimney repair service in Liverpool.
What affects the cost?
Access is the main factor: a pot on a low bungalow stack may be reached with a roof ladder, while a tall stack on a three-storey villa needs scaffold. The number of pots, whether the flaunching needs renewing, and the type of cap or cowl also matter. Doing pot work at the same time as repointing or a rebuild often makes sense because access is already in place. See our chimney repair cost guide for more.
When to call
Like any chimney repairs in Merseyside, pot work is best done early. Call if a pot is cracked or loose, if flaunching is breaking up, if birds are nesting in a flue, or if you have damp from a disused chimney. A loose pot can fall in high wind, so do not leave it.
Cracked pot or birds in the chimney?
Call 07777 659786 or send your details. Tell us how many pots there are and which flues are used, and we will call you back.
Frequently asked questions
Should I cap my unused chimney?
Yes, but with a vented cap rather than sealing it solid. A vented cap keeps rain out while letting the flue breathe. Fit a vent in the blocked-up fireplace too, so air can move through. Sealing both ends traps moisture and can cause condensation damp on the chimney breast.
How do I stop birds nesting in my chimney?
A bird guard or mesh cowl on the pot stops jackdaws and other birds getting into the flue. If the flue is in use, the guard must suit the appliance and be checked so it does not clog with soot. Nesting birds are protected by law, so guards are best fitted outside the nesting season.
Will a cowl stop smoke blowing back into my room?
An anti-downdraught cowl can help where wind blows down the flue, especially on exposed or low stacks. Smoke problems can also come from a blocked flue, a short stack, poor ventilation in the room or the wrong appliance, so have the flue swept and checked by a qualified chimney sweep first.
Can a cracked chimney pot fall off?
Yes. A cracked pot or one set in broken flaunching can loosen and fall, especially in high wind. If you can see a pot leaning or damaged, keep clear of the area below and have it checked. We can remove and replace it, renewing the flaunching at the same time.
Do you sweep chimneys?
No. We repair and maintain the stack, pots and caps but do not sweep flues. For open fires and stoves, please use a qualified chimney sweep, who can also confirm the flue is clear and drawing properly before any cap or cowl is fitted to a flue that is in use.
Can you cap just one flue on a shared stack?
Yes. Each pot usually serves a separate flue, so one can be capped while another stays open. On a shared stack we check carefully which pot serves which house and flue first, so we never cap a neighbour’s working flue.